Recently, in technology where electrons are emitted by an electric field without heating a negative electrode (cathode electrode), a so-called electron emission element of a surface emission type has been proposed (see Patent Document 1). The electron emission element has an aperture (emission concave portion) which penetrates an insulation layer and a gate electrode layer stacked on an electron emission layer and a carbon layer stacked on the gate electrode layer and an inner surface of the aperture, and emits electrons from an electron emission layer exposed at a bottom of the aperture by applying voltage to the gate electrode layer.
[Patent Document 1] WO2007-114103